Question: Evaluate the following expression when $x = 3$ and $y = 3$. $3$ $x$ $ + 3$ $y$ $ + 7$
Solution: Substitute $3$ for ${x}$ and $3$ for ${y}$ $ = 3{(3)} + 3{(3)} + 7 $ $ = 9 + 9 + 7 $ $ = 25$